Process of making molds for duplicating phonograph-records.



' No.77&617. PATENTED NOV11,190$

A.P.WURTH. PROCESS OF MAKING MOLDS FOR DUPLIOATING PHONOGRAPH RECORDS.

APPLIOATION FILED MAY 24, 1904. N0 MODEL. 2 SHEETSSHBET 1.

3 m0 MARCO) WITNESSES: l/VVE/VTOI? )6 6? m 22M hwy/QM BY ATTORNEY No.773,617. PATENTED NOV. 1, 1904.

' A.-P. WURTH. PROCESS OF MAKING MOLDS FOR DUPLIGATING PHONOGRAPHRECORDS.

APPLIGATION FILED MAY 24, 1904.

no MODEL. 2 sHEETs-sIiEnT 2.

mm 8858: INVENTOI? do? 7 7 AM 5 774614 ATTORNEY I ll UNITED STATESPatented November 1, 1904.

PATENT OFFICE.

ALBERT F. \VURTH, OF ORANGE, NEW JERSEY, ASSIGNOR TO NEW JERSEY PATENTCOMPANY, OF ORANGE, NEW JERSEY, A COR- PORATION OF NEW JERSEY.

PROCESS OF MAKING MOLDS FOR DUPLICATING PHONOGRAPH-RECORDS.

SPECIFICATION forming part of Letters Patent No. 773,617, dated.November 1, 1904.

Application filed May 24, 1904. Serial No. 209,566. (No model.)

To all whmn it 777/(bZ/ concern:

Be it known that I, ALBERT F. VVURTH, of 18 Snyder street, Orange, inthe county of Essex, State of New Jersey, have invented certainImprovements in Processes of Making Molds for DuplicatingPhonograph-Records, of which the following is a description.

At the present time many thousand molds are in use for producingduplicate copies of phonograph-records by pressing, casting, clipping,and analogous processes well known to persons skilled in the art. Thesemolds are in the form of cylinders generally with a very slightlytapered bore and carrying the negative representation of the record inrelief thereon. It is desirable for commercial reasons that eachphonograph-record should be molded with the name of the particularselection to do away with the necessity of employing separate tags orlabels which frequently become lost or misplaced, and this can be doneeffectively only when the mold itself is provided with an intaglio ofthe matter which thus requires to be molded on the record. I have foundthat it is possible to reconstruct the modern cylindrical molds byapplying an addition thereto carrying the titles of the correspondingselections, which will therefore be molded simultaneously with theproduction of the duplicate records and that this may be done in such away as to show no perceptible joint with the original mold. I am thusenabled to make use of a large number of cylindrical molds now inexistence which would otherwise have to be discarded and the cost ofwhich has amounted to many thousands of dollars. Besides thisconsiderable time would be required to make entirely new molds, while byutilizing my invention these old molds may be made over at a slight costand in very little time.

In order that my invention may be better understood, attention isdirected to the accompanying drawings, forming-a part of thisspecication, in which- Figure 1 represents a sectional view of anordinary phonograph-mold; Fig. 2, a corresponding view illustrating themanner of converting it into an improved mold wherein the name of theselection will be molded on each duplicate formed therein and showingthe parts assembled in the plating-bath; Fig. 3, a similar view of thecompletely-finished mold, and Fig. 4 a plan view of one of the wax plugson which the additional plating takes place.

In the views corresponding parts are represented by the same numerals ofreference.

The mold 1, which is in the form of a copper shell, carries the usualnegative representation of the phonograph-record on its bore. Ordinarilythis mold is very slightly tapered and is generally gold-plated ornickelplated on the record-surface to prevent oxidation. I take one ofthese molds and shorten it by cutting off the end on the line a m, and Ithen preferably bevel off this end to form an inclined shoulder 2,although this is not absolutely necessary. I now take a plug 3, made,preferably, of the ordinary wax-like phonographic recording material andof the shape shown, formed with the shoulder A slightly rounded, asillustrated. On this shoulder I preferably engrave in any suitable waythe name of the desired selection, as shown in form 4, together with thetrade-mark and number, if desired. Very excellent results have beensecured in practice with an ordinary pantograph engraving-machine.Having prepared the plug 3 in this way the latter is fitted veryaccurately in the beveled end of the mold 1, and this is preferablyeffected by making the plug of a diameter very slightly larger than thebore of the mold and then contracting it diametrically by a reduction intemperature, so as to permit its introduction into the mold. Preferablybefore the plug is thus introduced it is finely coated witha very thinconducting-filmfor example, of graphite or of a finely-dividedmetalapplied by a process of vacuous deposit. It will be also understoodthat this conducting-film may be applied to the plug after the latterhas been introduced within the mold, although this is not so desirable,owing to the liability of not covering the entire wax surface, resultingin the formation of a joint or seam in the finished mold, which wouldtherefore appear in the completed duplicates. 1 now electroplate on theconductingfihn a suitable metal to form an extension of the mold, whichoperation may be performed in any suitable way. For instance, the shelland plug may be clamped between two disks 5 and 6 by means of a bolt 7and nut 8, a soft-rubber washer 9 being interposed between the disk 6and the plug 3 to exclude the solution from the interior of the mold. Inorder to prevent the possibility of plating on the bolt 7, the latter ispreferably covered by a rubber sleeve 10, as shown. For the same reasonto prevent a deposit on the outside of the mold except on the shoulder9. the mold is protected by a wrapping of insulated tape or of any othersuitable material 11. The mold as thus equipped is supported in aplating-bath 12 from a rod 13, connected with one pole of the generatoror other source of supply let, the other pole thereof being connected toanodes 15 in the usual way.

The level of the solution is shown by the line 1 The hook 16, engagingthe conducting-rod 13, connects with a copper ring 17, embedded in theunder face of the disk 5, (the latter being usually made of hardrubber,) so

as to form a connection with the source of' supply 1s and to permit adeposit 18 to be formed on the conducting film or coating of the plug 3as well as upon the shoulder 2 of the mold. The electrodepositedaddition 18 becomes as intimately connected with the mold as if weldedthereto, so that it may be turned off on its outside flush with the moldafter the electrodeposition has been completed. The plug 3 is nowremoved from the mold either by shrinking it out or by breaking the plugto pieces or by melting the material thereof, after which the outside ofthe extension 18 and the bottom edge of the cylindrical neck 19 aretrimmed off to form the complete mold, as shown in Fig. 8.

11 in carrying the operations into effect the plug 3 has been coatedwith gold by a Vacuousdeposit process, obviously the interior of theelectroplated extension or addition will be gold-plated, and henceprotected from oxidation. If, however, graphite is used for coating theplug, the entire mold may be plated on its interior with gold or nickel,or if the film on the original mold is in good condition the interior ofthe extension alone may be plated with gold or nickel.

1 find, however, v

that this is not strictly necessary, since the extension does not carryany part of the record-surface, and hence it is not so important toprevent any bad effects from slight oxidation. I find that by making themold in this way the joint between the extension 18 and the originalmold1 can hardly be detected under the microscope, nor does it result in anyappreciable or audible disturbance in reproducing from records formedin' the complete mold.

These molds are capable of effective use in connection with any suitableduplicating process; but they are preferably used in connection withprocesses wherein a molten wax-like material is introduced into the moldand allowed to set therein to take an impression therefrom, after whichthe finished duplicate is removed by shrinking it diametrically andremoving it longitudinally, as described in patent to Thomas A. Edison,No. 667,662, dated February 5, 1901.

Having now described my invention, what I claim as new therein, anddesire to secure by Letters Patent, is

1. The process of securing an addition to a phonograph-mold, whichconsists in introducing a conducting-plug into the end of the mold andin electroplating a metal on said plug and on the mold, substantially asset forthu 2. The process of securing an addition to a phonograph-mold,which consists in beveling the end of the mold, in introducing aconducting-plug into the mold and in electroplating on said plug and onthe beveled portion of the mold, substantially as set forth.

3. The process of securing an addition to a phonograph-mold, whichconsists in introducing into the mold a plug having a conductingcoatingthereon and in electroplating a metal on said plug and on the end of themold, substantially as set forth.

1. The process of securing an addition to a phonograph-mold, whichconsists in shrinking a conducting-plug into the end of the mold and inelectroplating a metal upon said plug and upon the end of the mold,substantially as set forth.

This specification signed and witnessed this 23d day of May, 1904:.

ALBERT F. \VURTH.

WVitnesses:

FRANK L. DYER,

A. R. KLEHM.

